Wireless communication networks transfer data communications. Wireless communication networks use wireless protocols, such as Long Term Evolution (LTE), Evolution Data Optimized (EVDO), Code Division Multiple Access (CDMA), Global System for Mobile communications (GSM), High Speed Packet Access (HSPA), and the like. Wireless communication networks include various network elements, such as wireless access systems and network gateway systems. Examples of network elements include base stations, access nodes, eNodeBs, Mobility Management Entities (MMEs), Home Subscriber Servers (HSSs), Policy and Charging Rules Functions (PCRFs), Serving Gateways (S-GWs), Packet Data Network (PDN) Gateways (P-GWs), and Internet Multimedia Subsystem (IMS) servers.
Data communications are transferred through wireless communication networks by being forwarded from network element to the network element until the data communications reach their destination. The routing process usually directs forwarding on the basis of databases or routing tables. Network elements have internal and/or external databases containing entries with routing instructions.
For example, setting up a Voice over Internet Protocol (VoIP) call requires routing signaling and messages between various LTE network elements. In a simplified example, a User Equipment (UE) attaches to an eNodeB. The eNodeB transfers the attach request to the appropriate MME. The MME queries the HSS to authenticate the UE. The HSS sends authentication information to the MME. The MME authenticates the UE. The MME also transfers a session request to the S-GW. The S-GW transfers the session request to the appropriate P-GW. The P-GW returns a session response to the S-GW, which forwards the session response to the MME. The MME then transfers a bearer request to the eNodeB. The eNodeB transfers a Radio Resource Connection (RRC) configuration to the UE and sends a bearer accept response to the MME.